21012969 has 8 divisors (see below), whose sum is σ = 29665440. Its totient is φ = 13184576.

The previous prime is 21012913. The next prime is 21012991. The reversal of 21012969 is 96921012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21012969 - 2⁹ = 21012457 is a prime.

It is a super-2 number, since 2×21012969² = 883089732389922, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21012569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 205959 + ... + 206060.

It is an arithmetic number, because the mean of its divisors is an integer number (3708180).

Almost surely, 2^21012969 is an apocalyptic number.

It is an amenable number.

21012969 is a deficient number, since it is larger than the sum of its proper divisors (8652471).

21012969 is a wasteful number, since it uses less digits than its factorization.

21012969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412039.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 21012969 is about 4583.9905104614. The cubic root of 21012969 is about 275.9492003754.

The spelling of 21012969 in words is "twenty-one million, twelve thousand, nine hundred sixty-nine".